title: Characterizing pesticide sorption and degradation in microscale biopurification systems using column displacement experiments.
abstract: Biopurification systems treating pesticide contaminated water are very efficient, however they operate as a black box. Processes inside the system are not yet characterized. To optimize the performance, knowledge of degradation and retention processes needs to be generated. Therefore, displacement experiments were carried out for four pesticides (isoproturon, bentazone, metalaxyl, linuron) in columns containing different organic mixtures. Bromide, isoproturon and bentazone breakthrough curves (BTCs) were well described using the convection-dispersion equation (CDE) and a first-order degradation kinetic approach. Metalaxyl and linuron BTCs were well described using the CDE model expanded with Monod-type kinetics. Freundlich sorption, first-order degradation and Monod kinetics coefficients were fitted to the BTCs. Fitted values of the distribution coefficient K(f,column) were much lower than those determined from batch experiments. Based on mobility, pesticides were ranked as: bentazone>metalaxyl-isoproturon>linuron. Based on degradability, pesticides were ranked as: linuron>metalaxyl-isoproturon>bentazone.
authors.affiliation: Laboratory of Crop Protection Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium. tineke.dewilde@UGent.be
authors.forename: Tineke
authors.initials: T
authors.lastname: De Wilde
authors.forename: Jan
authors.initials: J
authors.lastname: Mertens
authors.forename: Jirka
authors.initials: J
authors.lastname: Simunek
authors.forename: Kristel
authors.initials: K
authors.lastname: Sniegowksi
authors.forename: Jaak
authors.initials: J
authors.lastname: Ryckeboer
authors.forename: Peter
authors.initials: P
authors.lastname: Jaeken
authors.forename: Dirk
authors.initials: D
authors.lastname: Springael
authors.forename: Pieter
authors.initials: P
authors.lastname: Spanoghe
mesh_terms: D000327:Adsorption; D000409:Alanine / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D001581:Benzothiadiazines / Q000493:pharmacokinetics; D001711:Biotransformation; D002627:Chemistry, Physical; D045424:Complex Mixtures / Q000737:chemistry; D008044:Linuron / Q000493:pharmacokinetics; D008956:Models, Chemical; D010575:Pesticides / Q000493:pharmacokinetics*; D010671:Phenylurea Compounds / Q000493:pharmacokinetics; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics*; D018508:Water Purification / Q000379:methods*
chemical_list: D001581:Benzothiadiazines; D045424:Complex Mixtures; D010575:Pesticides; D010671:Phenylurea Compounds; D014874:Water Pollutants, Chemical; D008044:Linuron; C028175:metalaxyl; C028904:isoproturon; D000409:Alanine; C002003:bentazone